Power outage emergency light circuit (3)

Figure 283 is a power outage emergency lighting controller. It has only two external terminals and can directly replace the ordinary
switch. When there is power, it can control the on and off of the light 1El like an ordinary switch ; when there is a power outage, it can be used It
controls the brightness of Xiaowu E2.
    In the figure, the left side of the dotted line is the ordinary lighting circuit, and the right side is the power outage emergency lighting controller. When the switch S is turned on
, VD7 is reverse biased and cut off, so the lights El and l:2 are not on. When there is power, such as the Taiwan r switch . S 220V
AC mains power is rectified by El, VT)l - VD4. At this time, VD5 is turned on, and after VD5 is stabilized, a DC voltage of about 6V can be
formed . At this time, the alternating current forms an old path through vS, causing the lamp to emit light.
The voltage value at both ends of the Ej is about 6V lower than the conventional 220V. This will not greatly affect the brightness of the bulb F1
. At this time, VD7 is still off, so
E2 still does not emit light. At the same time, the voltage at both ends of (,
can pass through V D3, VD6 and R to
store electricity in battery G. If the power grid suddenly loses power, El
will shut down, VD5 and VD6 will be reverse-
biased , and battery G will pass through R., Turn S and
VD7 to R to send power to the base of VT1.
VT1 and VT? are turned on, and the small lamp E2 is energized and
emits light for emergency lighting. If emergency lighting is not needed , just turn on S to turn off
E2.
.
    The power of the lighting lamp El is restricted by the power dissipation of the voltage regulator tube vs. The power of the lighting lamp El should not exceed
60W. E2 can use a small light bulb of 3 8-4. 8V, () 3A. vs can be t{jtwoL 6V, 1W voltage regulator tubes
are used in parallel. G uses 4 cells of nickel-cadmium or nickel-hydrogen batteries connected in series. Other component parameters are shown in the figure, and there are no special requirements
.